Cargo containers for overland and marine freight handling are produced in various standard sizes, including, among others, containers of 20, 40, 45, 48 and 53 feet lengths, as well as 96 inch and 102 inch widths.
These containers are typically provided with mounting fixtures used in securing the containers with respect to various vehicles or other cargo containers. The mounting fixtures are positioned in standard arrangements on both the top and bottom of the containers. For example, a conventional I.S.O. cargo container is 40 feet long and 96 inches wide, and includes mounting fixtures at each of the eight corners of the container.
It is typical to transport together many containers having various sizes. Different techniques for handling cargo containers having different lengths are disclosed, for example, in U.S. Pat. No. 3,646,609 to Bodenheimer, U.S. Pat. No. 4,108,326 to Bertolini, and U.S. Pat. No. 5,183,375 to Fenton et al. (hereinafter "Fenton").
Bodenheimer discloses support points at intermediate positions along the length of cargo containers. The support points are spaced apart to match the mounting fixtures of shorter cargo containers. When stacking cargo containers of different lengths, the support points of a longer cargo container are vertically aligned with the mounting fixtures of a shorter cargo container. A disadvantage of Bodenheimer is that including support points in a wider cargo container to match the mounting fixtures of a narrower cargo container would obstruct the interior capacity of the wider cargo container. Further, because the location of support points is a function of the relative numbers of side-by-side wider and narrower containers, a large number of interior support points would be required inside both wider and narrower cargo containers to ensure each mounting fixture could be aligned with a support point.
Bertolini discloses attaching an adapter frame to the ends of shorter cargo containers to provide mounting fixtures matching longer cargo containers. A disadvantage of Bertolini is the lack of any provision for stacking cargo containers having different widths. As with Bodenheimer, the position of mounting fixtures is dependent on the relative numbers of side-by-side wider and narrower cargo containers. Further, Bertolini fails to disclose laterally offsetting the outboard mounting points of the adapter frames to accommodate the cargo containers of different widths.
Fenton also discloses an adapter frame for supporting one or two shorter cargo containers on a relatively longer cargo container. Fenton is directed to a single column of stacked cargo containers having the same width to be used on a railway car.
Typically, additional lashing (e.g. cables) is required to compensate for the inability to align and connect all the mounting fixtures of stacked cargo containers having different widths. The additional lashing is both time consuming and expensive to fit and remove.
There is a need for a simple container stacking apparatus that can stack containers having different dimensions, without any of above-noted drawbacks. The present invention meets this need.